Sphere of Flame

Eruption - Whenever another source you control deals noncombat, nonfight damage to a creature or player, you may pay {x}{r} and tap Sphere of Flame. If you do, Sphere of Flame deals X damage divided evenly, rounded down, among any number of targets. Pay {1} for each target beyond the first.
An ancient artifact, it is known for spontaneously combusting and shooting out balls of fire.